Architectural trends are extending outside the home, with a desire for low maintenance and high style incoporated into the design at peak levels. Marcus Hiles has seen the demand for sustainable, cost-reducing open-air spaces rise in recent years. Rainwater/graywater harvesting and permeable pavement are popular systems being put into place at increasing levels. Utilizing a rooftop collection system, rainwater harvesting redirects moisture that falls onto the roof to a well, where it is then treated and repurposed on-site. Graywater repurposes previously used domestic wastewater to toilets and other non-drinking purposes, lessening the need for fresh water and sterilization. Another seemingly new idea for environmentally minded construction, permeable paving, actually originated thousands of years ago when people first made roads by putting stones in beds over the ground. The design allows the rain to pass through small openings between four layers of filtration (paving material, gravel, fabric, sand) and then be absorbed by the earth below. Benefits include lowering runoff and pollution, controlling the flow of storm water to gutters and drains, maintaining local groundwater supplies, and providing a skid resistant surface for walkways, patios and driveways. Many attractive permeable pavement patterns often incorporate crushed stone, brick, and recycled concrete.